Question

According to the generally question for conditional probability if P(AnB) = 5/7 and P(B) = 7/8 what is P(A|B)?

Answer 1

Hi!

P(A|B) means the probability A will happen given B has happened. P(AnB) is the probability both will happen, and P(B) is the probability B will happen.

You can figure out a formula from that, but here's the generally accepted one:

P(A|B) = P(AnB) / P(B)

P(AnB) = 5/7
P(B) = 7/8

Substitute values in:

P(A|B) = 5/7 / 7/8

P(A|B) = 5/7 * 8/7

P(A|B) = 40/49